1. Field of the Invention
The present invention relates to a lens driving apparatus, particularly to a lens driving apparatus that records data such as a program in an Electrically Erasable Programmable Read Only Memory (EEPROM) whose contents can be electrically reprogrammed, and that controls lenses in accordance with data stored in the EEPROM.
2. Description of Related Art
The use of TV cameras has been increasing with a need for digital broadcasting and a virtual studio, and control of the TV lens apparatus has been required to have high precision. Among such lens apparatuses, the digital control by a microcomputer has been greatly improved.
In controlling the lens apparatus by the microcomputer, programs for operating the microcomputer and respective optical data for lenses and so forth are required. The data required for such control by the microcomputer is written in a ROM in a manufacturing process, and is built in the lens apparatus or in the drive unit for driving the lens.
Because the lens apparatus of that type is globally marketed, the same type of program is naturally recorded in the ROM for the lens apparatus of the same type and is built in the lens apparatus or the drive unit (Japanese Patent Application Laid-open No.7-58993).
Although the program and the like which is recorded in the ROM and is built in the lens apparatus or the drive unit basically does not require updating data, yet update of program and the like is seldom required under following situations of users or manufacturers, for example:
1) change of versions by user (such as change of data for a lens accompanied by change of versions of the lens controller, or change of serial interface protocol);
2) change of versions by manufacturer (such as change in optical data and adjusting the data to a new product); and
3) program error (error in program which could not be found in an inspection in the factory).
Conventionally, in a case where such situation arises, a cover of the lens apparatus or the drive unit must be removed so as to replace the ROM or to reprogram the contents of the ROM by a ROM writer, which cause troublesome processes and increase of cost. Further, collecting the globally marketed lens apparatus and replacing the ROM are difficult, and changes of programs has been troublesome to both the manufacturers and the users.
The present invention has been developed in view of the above-described circumstances, and has as its object the provision of a lens driving apparatus in which the contents such as a program stored in a ROM can be easily updated.
In order to achieve the above-described object, the present invention is directed to a lens driving apparatus, comprising: a ROM which stores data used for controlling the lens driving apparatus, contents of the ROM being electrically reprogrammable; a data obtaining device which obtains new data from an external device; and a reprogramming device which reprograms the contents of the ROM with the new data.
Preferably, the lens driving apparatus of the present invention further comprises a control device which measures power source voltage supplied to the lens driving apparatus, the control device inhibiting the reprogramming device from reprogramming the contents of the ROM when the power source voltage is lower than a required voltage for reprogramming the contents of the ROM.
Preferably, the lens driving apparatus of the present invention further comprises an alarm device, the control device causing the alarm device to alarm when the power source voltage is lower than the required voltage.
According to the present invention, data such as a program required for controlling a lens is recorded in a memory (ROM) whose contents can be electrically reprogrammed and used exclusively for reading out, and new data is obtained from an external unit such as a personal computer, then the data in the ROM can be updated to be the new data. Therefore, exchange of ROMs and data writing into the ROM with special tools are unnecessary, and further, a user can obtain the new data from the manufacturer and the like by a communication means such as the internet, or the user can update the user""s own ROM data by obtaining a record medium in which the new data is recorded, without always handing the actual lens apparatus to the manufacturer. Thus, the data such as a program can be changed in response to needs and as well as with low cost; hence the users and the manufacturers can easily change versions of a soft data for the lens system.